[PATCH 4.4 10/43] net: cavium: liquidio: Avoid dma_unmap_single on uninitialized ndata

From: Greg Kroah-Hartman
Date: Mon May 01 2017 - 18:07:01 EST

4.4-stable review patch. If anyone has any objections, please let me know.


From: Florian Fainelli <f.fainelli@xxxxxxxxx>

commit 8e6ce7ebeb34f0992f56de078c3744fb383657fa upstream.

The label lio_xmit_failed is used 3 times through liquidio_xmit() but it
always makes a call to dma_unmap_single() using potentially
uninitialized variables from "ndata" variable. Out of the 3 gotos, 2 run
after ndata has been initialized, and had a prior dma_map_single() call.

Fix this by adding a new error label: lio_xmit_dma_failed which does
this dma_unmap_single() and then processed with the lio_xmit_failed

Fixes: f21fb3ed364bb ("Add support of Cavium Liquidio ethernet adapters")
Reported-by: coverity (CID 1309740)
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Julia Lawall <julia.lawall@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/net/ethernet/cavium/liquidio/lio_main.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/cavium/liquidio/lio_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c
@@ -2823,7 +2823,7 @@ static int liquidio_xmit(struct sk_buff
if (!g) {
netif_info(lio, tx_err, lio->netdev,
"Transmit scatter gather: glist null!\n");
- goto lio_xmit_failed;
+ goto lio_xmit_dma_failed;

cmdsetup.s.gather = 1;
@@ -2894,7 +2894,7 @@ static int liquidio_xmit(struct sk_buff
status = octnet_send_nic_data_pkt(oct, &ndata, xmit_more);
if (status == IQ_SEND_FAILED)
- goto lio_xmit_failed;
+ goto lio_xmit_dma_failed;

netif_info(lio, tx_queued, lio->netdev, "Transmit queued successfully\n");

@@ -2908,12 +2908,13 @@ static int liquidio_xmit(struct sk_buff

return NETDEV_TX_OK;

+ dma_unmap_single(&oct->pci_dev->dev, ndata.cmd.dptr,
+ ndata.datasize, DMA_TO_DEVICE);
netif_info(lio, tx_err, lio->netdev, "IQ%d Transmit dropped:%llu\n",
iq_no, stats->tx_dropped);
- dma_unmap_single(&oct->pci_dev->dev, ndata.cmd.dptr,
- ndata.datasize, DMA_TO_DEVICE);
return NETDEV_TX_OK;